1339509 - Shift + Tab yields key === 'Unidentified' on Linux

Status: VERIFIED FIXED

(Core :: Widget: Gtk, defect, P3)

Description

[Julien Wajsberg [:julienw]]

STR:
1. Go to https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/code
2. scroll down to the first example;
3. Press "shift + tab"

Expected:
KeyboardEvent: key='Shift' | code='ShiftLeft'
KeyboardEvent: key='Tab' | code='Tab'

Actual:
KeyboardEvent: key='Shift' | code='ShiftLeft'
KeyboardEvent: key='Unidentified' | code='Tab'


Chrome does it as expected.

Comment 1

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

Works as expected on Windows 8.1, fails in Xubuntu 14.04 VM.

Comment 2

[Andrew Overholt [:overholt]]

Masayuki probably knows what's going on here.

Comment 3

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(sick)]

Oh, this is a simple bug.

Comment 4

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(sick)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=fb8dbeb96cf3

Comment 5

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(sick)]

Attachment: Bug 1339509 Map ISO_Left_Tab to DOM Tab key

Shift + Tab key combination causes ISO_Left_Tab keysym instead of Tab.  It should be mapped to DOM Tab key.

Review commit: https://reviewboard.mozilla.org/r/113412/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/113412/

Comment 6

[Karl Tomlinson (:karlt)]

Comment on attachment 8838475 [details]
Bug 1339509 Map ISO_Left_Tab to DOM Tab key

https://reviewboard.mozilla.org/r/113412/#review115342

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0ba503d21240
Map ISO_Left_Tab to DOM Tab key r=karlt

Comment 8

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/0ba503d21240

Comment 9

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(sick)]

Comment on attachment 8838475 [details]
Bug 1339509 Map ISO_Left_Tab to DOM Tab key

Approval Request Comment
[Feature/Bug causing the regression]:　Miss mapping of KeyboardEvent.key value on Linux (Chromium maps the keysym to "Tab" correctly).
[User impact if declined]: Linux users might meet this bug when web page handles Shift+Tab key with KeyboardEvent.key.
[Is this code covered by automated tests?]: No.
[Has the fix been verified in Nightly?]: Yes (confirmed with local build built from m-c).
[Needs manual test from QE? If yes, steps to reproduce]: Can do it easy:
1. Open https://w3c.github.io/uievents/tools/key-event-viewer.html
2. Set focus to the editor.
3. Type Shift+Tab
Then, "Tab" should be displayed at "key" of "UI Events" column.
[List of other uplifts needed for the feature/fix]: No.
[Is the change risky?]: No.
[Why is the change risky/not risky?]: Just adding a mapping from native keysym, GDK_ISO_Left_Tab to "Tab".
[String changes made/needed]: No.

Comment 10

[Julien Cristau [:jcristau]]

Comment on attachment 8838475 [details]
Bug 1339509 Map ISO_Left_Tab to DOM Tab key

add a missing key mapping for gtk, aurora53+, beta52+

Is the lack of automated tests something we should address?

Comment 11

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(sick)]

(In reply to Julien Cristau [:jcristau] from comment #10)
> Is the lack of automated tests something we should address?

Unfortunately, we don't have any API to emulate native keyboard event on Linux (I forgot the bug#). Although, we have it on Windows and macOS. That's the reason why I failed to detect this bug at creating the mapping table.

Comment 12

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/3cd7637cb873

Comment 13

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/732a5221be43

Comment 14

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-esr52/rev/732a5221be43

Comment 15

[Andrei Vaida [:avaida]]

Reproduced the issue with an affected build (51.0, 20170118123726) using the instructions from Comment 0 on Ubuntu 16.04 x64. The output was:

> KeyboardEvent: key='Shift' | code='ShiftLeft'
> KeyboardEvent: key='Unidentified' | code='Tab'


This is verified fixed on Ubuntu 16.04 x64 using: 

    - 52.0b9-build2 (20170223185858),
    - 53.0a2 (2017-02-24),
    - 54.0a1 (2017-02-24)

with the following output now displayed correcttly across these branches:

> KeyboardEvent: key='Shift' | code='ShiftLeft'
> KeyboardEvent: key='Tab' | code='Tab'

Comment 16

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(sick)]

Thank you, that's the expected result!